<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    "use strict"
    //第一种
    function  a(x){
        if(x>0){
            return "yes";
        }else{
            return "no";
        }
    }
    console.log(a(1));
    
    //第二种
    let b = function(x){
        if(x>0){
            return "yes";
        }else{
            return "no";
        }
    }
    console.log(b(-1));

</script>

</body>
</html>